Three Essays Due On My Ipad

Ielts how to present a project proposal

the system of collecting and synthesis of the available data meanwhile has no uniform scientific concept, is separated and even not by all is supported. Social-and-ecological model of Moscow – a problem of the forthcoming researches.

Agricultural areas are very various on an environment, types of land use and extent of development. Nevertheless environmental problems in them have much in common. It is connected with the following circumstances:

The main changes of soils in agriculture are connected with mechanical impact on it and with application of fertilizers. Plowing changes a soil profile, destroys structure, leads to impoverishment of the top horizons, promotes strengthening of a water erosion and a deflation. Along with loosening there is also a consolidation of the soil.

The vegetable cover of the cities usually is almost completely presented by "cultural plantings" – parks, squares, lawns, flower beds, avenues. The structure of anthropogenous fitotsenoz does not correspond to zone and regional types of natural vegetation. Therefore development of green plantings of the cities proceeds in artificial conditions, is constantly supported by the person. Perennial plants in the cities develop in the conditions of strong oppression.

Also the soil cover of urban areas is exposed to radical restructuring. On big squares, under highways and quarters, it is physically destroyed, and in zones of recreations – parks, squares, the yards – strongly is destroyed, becomes soiled household waste, harmful substances from the atmosphere, is enriched with heavy metals, nakedness of soils promotes a water and wind erosion.

City sewage for 98,6% is exposed to biological cleaning, however a lot of sand, salts, the acidified and warm water nevertheless gets to reservoirs. Deficiency of water – one of factors of control of housing construction. From 1650 main industrial enterprises the system of reverse water supply is had only 16

Thermal influence increases temperature in the city by 3-5 °C, the bezmorozny period for 10-12 days and snowless – for 5-10 days. Heating and raising of air in the center causes subcurrent it from the suburb – both from a forest-park belt, and from industrial zones.